New olenellid trilobites of the Digermul Peninsula, Finnmark, Northern Norway –Constraints on lower Cambrian biostratigraphy

• The Ediacaran to Early Ordovician succession on the Digermul Peninsula measures 1500m,mostly consisting of well-preserved siliciclastics. The Ediacaran–Cambrian transitionhere contains a rich suite of trace fossils comparable with that of the GSSP section inNewfoundland. New discoveries of Treptichnus pedum indicate that the upper part ofthe Manndraperelva Member is Cambrian. The first trilobites are found in the Uppermember of the Doulbasgaissa Formation. Previously only a few Kjerulfia lata specimenswere known, but fieldwork in the Summer of 2011 added new material of this species anda new Elliptocephala species. Both Kjerulfia lata and acritarchs place the trilobite-bearinglevel in the Holmia kjerulfia Assemblage Zone. The higher stratigraphic position of theDoulbasgaissa Formation suggested by Nielsen and Schovsbo (2011) is thus contradicted.With three olenellids and other shelly fauna, the Holmia kjerulfia Assemblage Zone in theMjösa area shows a diversity not seen on Digermul. However, the two olenellids in Digermulare unusual in Baltoscandia, where most species are known from isolated occurrences and fewor incomplete specimens. Comparison with the new material and constraints using acritarchsshould provide significant improvements on the correlation of this level in Baltoscandia.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Annan geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Other Earth and Related Environmental Sciences (hsv//eng)

Nyckelord

Lower Cambrian

Digermulen

Norway

acritarchs

trace fossils

trilobites

Publikations- och innehållstyp

vet (ämneskategori)

kon (ämneskategori)